1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162

/*
 * File: filter.rs
 * Project: defined
 * Created Date: 05/10/2023
 * Author: Shun Suzuki
 * -----
 * Last Modified: 05/10/2023
 * Modified By: Shun Suzuki (suzuki@hapis.k.u-tokyo.ac.jp)
 * -----
 * Copyright (c) 2023 Shun Suzuki. All rights reserved.
 *
 */

use crate::defined::{float, PI};

#[repr(C)]
pub struct FilterPhase {
    pub phase: i16,
}

impl FilterPhase {
    pub fn to_phase(d: float, cycle: u16) -> i16 {
        (((d / (2.0 * PI) * cycle as float).round() as i32) % (cycle as i32)) as _
    }

    pub fn set(&mut self, d: float, cycle: u16) {
        self.phase = Self::to_phase(d, cycle);
    }
}

#[repr(C)]
pub struct FilterDuty {
    pub duty: i16,
}

impl FilterDuty {
    pub fn to_duty(d: float, cycle: u16) -> i16 {
        (cycle as float * d.clamp(-1., 1.).asin() / PI).round() as _
    }

    pub fn set(&mut self, d: float, cycle: u16) {
        self.duty = Self::to_duty(d, cycle);
    }
}

#[cfg(test)]
mod tests {
    use std::mem::size_of;

    use super::*;
    use crate::defined::PI;

    #[test]
    fn phase_filter() {
        assert_eq!(size_of::<FilterPhase>(), 2);

        let mut d = 0x0000i16;

        let cycle = 4096;
        unsafe {
            (*(&mut d as *mut _ as *mut FilterPhase)).set(0.0, cycle);
            assert_eq!(d, 0);

            (*(&mut d as *mut _ as *mut FilterPhase)).set(PI, cycle);
            assert_eq!(d, 2048);

            (*(&mut d as *mut _ as *mut FilterPhase)).set(1.5 * PI, cycle);
            assert_eq!(d, 2048 + 1024);

            (*(&mut d as *mut _ as *mut FilterPhase)).set(2.0 * PI, cycle);
            assert_eq!(d, 0);

            (*(&mut d as *mut _ as *mut FilterPhase)).set(3.0 * PI, cycle);
            assert_eq!(d, 2048);

            (*(&mut d as *mut _ as *mut FilterPhase)).set(-PI, cycle);
            assert_eq!(d, -2048);

            (*(&mut d as *mut _ as *mut FilterPhase)).set(-1.5 * PI, cycle);
            assert_eq!(d, -2048 - 1024);

            (*(&mut d as *mut _ as *mut FilterPhase)).set(-2.0 * PI, cycle);
            assert_eq!(d, 0);
        }

        let cycle = 2000;
        unsafe {
            (*(&mut d as *mut _ as *mut FilterPhase)).set(0.0, cycle);
            assert_eq!(d, 0);

            (*(&mut d as *mut _ as *mut FilterPhase)).set(PI, cycle);
            assert_eq!(d, 1000);

            (*(&mut d as *mut _ as *mut FilterPhase)).set(1.5 * PI, cycle);
            assert_eq!(d, 1000 + 500);

            (*(&mut d as *mut _ as *mut FilterPhase)).set(2.0 * PI, cycle);
            assert_eq!(d, 0);

            (*(&mut d as *mut _ as *mut FilterPhase)).set(3.0 * PI, cycle);
            assert_eq!(d, 1000);

            (*(&mut d as *mut _ as *mut FilterPhase)).set(-PI, cycle);
            assert_eq!(d, -1000);

            (*(&mut d as *mut _ as *mut FilterPhase)).set(-1.5 * PI, cycle);
            assert_eq!(d, -1000 - 500);

            (*(&mut d as *mut _ as *mut FilterPhase)).set(-2.0 * PI, cycle);
            assert_eq!(d, 0);
        }
    }

    #[test]
    fn duty_filter() {
        assert_eq!(size_of::<FilterDuty>(), 2);

        let mut d = 0x0000i16;

        let cycle = 4096;
        unsafe {
            (*(&mut d as *mut _ as *mut FilterDuty)).set(0.0, cycle);
            assert_eq!(d, 0);

            (*(&mut d as *mut _ as *mut FilterDuty)).set(0.5, cycle);
            assert_eq!(d, 683);

            (*(&mut d as *mut _ as *mut FilterDuty)).set(1.0, cycle);
            assert_eq!(d, 2048);

            (*(&mut d as *mut _ as *mut FilterDuty)).set(1.5, cycle);
            assert_eq!(d, 2048);

            (*(&mut d as *mut _ as *mut FilterDuty)).set(-0.5, cycle);
            assert_eq!(d, -683);

            (*(&mut d as *mut _ as *mut FilterDuty)).set(-1.0, cycle);
            assert_eq!(d, -2048);
        }

        let cycle = 2000;
        unsafe {
            (*(&mut d as *mut _ as *mut FilterDuty)).set(0.0, cycle);
            assert_eq!(d, 0);

            (*(&mut d as *mut _ as *mut FilterDuty)).set(0.5, cycle);
            assert_eq!(d, 333);

            (*(&mut d as *mut _ as *mut FilterDuty)).set(1.0, cycle);
            assert_eq!(d, 1000);

            (*(&mut d as *mut _ as *mut FilterDuty)).set(1.5, cycle);
            assert_eq!(d, 1000);

            (*(&mut d as *mut _ as *mut FilterDuty)).set(-0.5, cycle);
            assert_eq!(d, -333);

            (*(&mut d as *mut _ as *mut FilterDuty)).set(-1.0, cycle);
            assert_eq!(d, -1000);
        }
    }
}